1. Field of the Invention
The present invention relates to a magnetic head slider, and a method of fabricating a magnetic head slider.
2. Description of the Related Art
Magnetic disk drives include a disk and a magnetic head slider supported by a suspension. The magnetic head slider has a floating surface (or flying surface) that is arranged opposed to the disk during the use of the magnetic head slider, and an electromagnetic transducer element that writes information in the disk or reads information from the disk. The floating surface has a plurality of rails. Airflow acting on the rails causes the magnetic head slider to float above the disk. The magnetic head slider is made mainly of Altic, and the portion of the magnetic head slider including the electromagnetic transducer element is made of alumina.
Japanese Unexamined Patent Publication (Kokai) No. 2000-173217 discloses a negative-pressure type magnetic head slider. The negative-pressure type magnetic head slider includes a front rail that extends in the transverse direction relative to the longitudinal direction of the magnetic head slider, and a pair of rear rails that are disposed with a given space retained behind the front rail. Airflow induced by the rotating disk generates buoyancy (or lift) at the front rail and rear rails. A step that is lower than the front rail is formed on the front side and the rear side of the front rail. Airflow flowing into an area located behind the step of the front rail after passing through the front rail generates a negative pressure on the rear side of the front rail. The magnetic head slider floats (or flies) at a relatively short distance from the disk, owing to the combination of the buoyancy and negative pressure. When the magnetic disk drive operates to make a steady-state rotation, the magnetic head slider floats while tilting in such a manner that the front part thereof floats more greatly than the rear part thereof.
Moreover, the floating surface of the magnetic head slider has a plurality of projections. The plurality of projections jut out more than the front rail and rear rails, and each of the projections has the same height. When the disk is stopped, the projections are in contact with the disk. This prevents the front rail and rear rails from coming into direct contact with the disk and being adhered to the disk. As the front rail and rear rails are not in direct contact with the disk, when the disk is rotated, airflow moves along the front rail and rear rails. This causes the magnetic head slider to float above the disk.
Moreover, a lubricant is applied to the disk. When a part of the floating surface of the magnetic head slider comes into contact with the disk or excessively approaches the disk, the lubricant sticks to the floating surface. This causes the magnetic head slider to be out of balance or adversely affects the electromagnetic transducer element.
Recently, the distance between the electromagnetic transducer element and the disk has become less along with an increasing demand for high-density recording to be achieved by the magnetic disk drive. A part of the magnetic head slider is therefore likely to come into contact with the disk. The magnetic head slider floats while tilting in such a manner that the front part thereof floats more greatly than the rear part thereof. The distance of the rear end of the floating surface from the disk is the shortest among all the parts of the floating surface. Therefore, the magnetic head slider is controlled so that the distance between the rear end of the floating surface and the disk can be retained at a predetermined value (typically called a minimum value).
The electromagnetic transducer element is located slightly ahead of the rear end of the floating surface. When the magnetic head slider tilts, the distance between the position on the floating surface at which the electromagnetic transducer element is located and the disk assumes a value a little larger than the minimum value. When the inclination (angle of pitch) of the magnetic head slider gets smaller, the difference between the distance of the position on the floating surface, in which the electromagnetic transducer element is located, from the disk, and the distance of the rear end of the floating surface from the disk also gets smaller. This situation is preferable because the electromagnetic transducer element can approach the disk. However, according to the prior art, each of the plurality of projections, intended to prevent the front rail and rear rails from being adhered to the disk, has the same height. Therefore, a layout of the magnetic head slider is restricted by some projections positioned at the rear side, and it is difficult to decrease the inclination (angle of pitch) of the magnetic head slider.